Surgical Aide Mémoire

** Colleague Zone - by invitation only **

This page provides a structured framework for planning skin cancer surgery.


It brings together three used decision tools, taught by the SCCA (SKin Cancer College Australasia)‍, ‍DRIPS, CHAIRS and PIG CARTS, to support clear thinking from diagnosis through to reconstruction.

Designed for use in real time, it is intended as a quick reference to guide decision-making, not replace clinical judgement.

“The Pen is More Dangerous than the Scalpel”
— Dr Charles Ayesa

DRIPS(Dr Jeremy Hays)

This Mnemonic was coined in 2022 by Dr Jeremy Hays as an aide to teach skin cancer doctors how to have a structured approach to defect closures

D – Defect
Size, shape, depth, anatomical site

R – RSTLs
Direction of closure and scar optimisation

I – Icebergs
Underlying structures at risk, potential complications e.g. free margin distortion

P – Pool
Pool or reservoir of skin that can be utilised for repair (“Peter to pay Paul”)

S – Surgical solution
Match technique to the above constraints

CHAIRS(by Dr Charles Ayesa)

This Mnemonic was coined in 2025 by Dr Charles Ayesa as an update to the DRIPS mnemonic as Mohs surgery is commonly used for facial excisions in Europe and North America, DRIPS did not account for the cancer treatment method, it may only be applicable after the Mohs process.

C – Cure the cancer
Choose the most appropriate oncologic approach (excision, staged, non-surgical, or referral)

H – Hole
Site, size, depth, and structures involved

A – Alignment / Area
RSTLs, cosmetic units, symmetry, and function

I – Icebergs / Incidents
Underlying structures at risk (nerves, vessels, cartilage, free margins)

R – Reservoir
Available adjacent tissue — “robbing Peter to pay Paul”

S – Solution / Salvage
Plan A, with contingency (Plan B/C, margin involvement strategy)

CASPERS(by Dr Paul Alsop)

This Mnemonic was coined by Dr Paul Alsop as a structured framework designed to guide clinicians from tumour assessment through to surgical solution, ensuring oncological safety and appropriate reconstruction.

C – Cancer
Histology, subtype, behaviour, margins, primary vs recurrent

A – Area
Lesion size, predicted defect, depth of excision

S – Site
Anatomical location, cosmetic unit, functional zone

P – Perils
Structures at risk, distortion, complications (e.g. free margins, nerves, function)

E – Elasticity
Skin mobility, laxity, direction of movement

R – Reserve
Available tissue for recruitment (“borrowed” skin), donor options

S – Solution
Match reconstruction to the above constraints

Core Principles

Clearance first, reconstruction second

Respect RSTLs and cosmetic units

Redistribute tension, don’t fight it

Protect free margins

Always have a backup plan

PIG CARTS(by Dr Robert Paver)

This Mnemonic was coined by Dr Robert Paver as an aide on how to approach a defect

P – Primary closure

I – Interpolation flap

G – Graft

C – Complex (combined closure)

A – Advancement flap

R – Rotation flap

T – Transposition flap

S - Secondary Intention

DRIPS – Defect Analysis Framework

(Jeremy Hays)

A practical tool to systematically assess a surgical defect before committing to closure.

D – Defect

  • Size (diameter and surface area)

  • Depth (dermis vs subcutis vs cartilage/periosteum)

  • Shape (round, oval, irregular)

  • Anatomical site (high vs low mobility regions)

  • Margin status (clear vs uncertain)

R – RSTLs (Relaxed Skin Tension Lines)

  • Determine optimal scar orientation

  • Align closure with natural lines where possible

  • Consider cosmetic subunits (particularly face)

  • Identify where tension will be visible vs concealed

I – Icebergs

  • Underlying critical structures:

    • Nerves (e.g. facial nerve branches)

    • Vessels

    • Cartilage (nose, ear)

  • Functional risks:

    • Free margin distortion (lip, eyelid, ala)

    • Structural collapse (nasal ala / valve)

  • Anticipate complications before closure choice

P – Pool (Reservoir of Tissue)

  • Tissue laxity and mobility

  • Directional availability of skin

  • Adjacent vs distant recruitment

  • “Borrowing” from cosmetic subunits

  • Limitations in tight areas (scalp, lower leg)

S – Surgical Solution

  • Match reconstruction to constraints above

  • Choose the simplest effective option

  • Escalate only when required

  • Always consider alternatives before committing

CHAIRS - Strategic Planning Framework

(Charles Ayesa)

Defines the overall surgical strategy before reconstruction begins.

C – Cure the Cancer

  • A curative defect is made following appropriate guidelines with reference to tumour size, location, subtype and tumour margin definition

  • Choose modality:

    • Standard excision

    • Staged excision / Mohs-type approach

    • Non-surgical options (where appropriate)

    • Referral if complexity exceeds scope

  • Prioritise oncological clearance over reconstruction

H – Hole

  • Depth and diameter of the resultant hole relative to the location informs the complexity of reconstruction and choice of closure techniques

  • Final defect after clearance:

    • Size

    • Depth

    • Location

  • Anticipate how margins will alter the defect

  • Plan reconstruction based on final, not initial lesion

A – Alignment / Area

  • RSTL alignment with respect to cosmetic boundaries allowing incisions to be optimally oriented, scars hidden and increases the chance of keeping the repair in a single cosmetic unit

  • Maintain symmetry across midline structures

  • Consider distortion of key landmarks

  • Think in aesthetic units rather than arbitrary defects

I – Icebergs / Incidents

  • Consider underlying anatomical structures, free margins and functional structures (e.g. internal nasal valve) that are at risk

  • Identify risks before they occur:

    • Nerve injury

    • Vascular compromise

    • Margin distortion

  • Consider patient-specific risks (age, comorbidities)

  • Plan to avoid predictable complications

R – Reservoir

  • The best skin reservoir(s) is identified - any proposed solution must effectively access this, otherwise the risk of complications rises steeply

  • Identify usable tissue:

    • Adjacent laxity

    • Regional recruitment

  • “Rob Peter to pay Paul” intelligently

  • Avoid over-tensioning donor sites

S – Solution / Salvage

  • Tailored closure methods based on defect characteristics and anatomical considerations ensure optimal functional and aesthetic outcomes. “Plan B” may be necessary

  • Define Plan A clearly

  • Pre-plan Plan B and C:

    • If closure fails

    • If margins are involved

    • If tissue behaves differently than expected

  • Good surgery anticipates failure pathways

CASPERS - Preoperative Decision Pathway

(Paul Alsop)

An overt planning framework for skin cancer surgery

CASPERS is a practical decision-making framework designed to guide clinicians from tumour assessment through to reconstructive planning. It is intended to support structured thinking before the first cut is made.

The framework moves in a deliberate sequence:

What is the cancer? How big will the problem be? Where is it? What is at risk? What tissue is available? What is the best solution?

C – Cancer

This step focuses on the biological and oncological features of the lesion:

  • Histological diagnosis

  • Subtype and behaviour

  • Well-defined vs poorly defined margins

  • Primary vs recurrent lesion

  • Aggressive features or higher-risk pathology

This is where the clinician decides whether the case is appropriate for:

  • standard excision

  • staged excision

  • margin-controlled surgery

  • non-surgical treatment

  • referral to a more experienced operator or specialist service

A – Area

This step considers:

  • lesion diameter

  • expected surgical margins

  • predicted post-excision defect

  • depth of excision

  • whether cartilage, muscle, periosteum, or other deeper structures may be involved

S – Site

This step addresses:

  • anatomical site

  • cosmetic unit or subunit

  • free margins

  • functional zones

  • whether the site is forgiving or unforgiving

Examples:

  • the cheek often tolerates tissue movement well

  • the nasal tip, eyelid, lip, ala, and earlobe tolerate distortion poorly

  • scalp and lower leg have limited laxity

Site is not just geography, it determines:

  • tension tolerance

  • scar visibility

  • flap design possibilities

  • functional risk

P – Perils

This step focuses on:

  • structures at risk

  • likely complications

  • functional consequences

  • cosmetic consequences

  • specific distortion risks

Examples include:

  • alar retraction

  • eyelid malposition

  • vermilion misalignment

  • earlobe distortion

  • nerve injury

  • vascular compromise

  • trapdoor effect

  • pinning or tethering

E – Elasticity

This step considers:

  • skin mobility

  • laxity

  • elasticity

  • age-related tissue characteristics

  • whether tension can be distributed safely

Some sites have abundant mobility. Others do not.

This directly influences:

  • whether primary closure is realistic

  • whether a flap is possible

  • whether a graft is more appropriate

  • whether closure will create distortion

R – Reserve

This step looks at the tissue reservoir available for repair:

  • adjacent recruitable skin

  • direction of usable tissue movement

  • donor areas within or across cosmetic units

  • whether there is enough reserve for flap design

This is the classic reconstructive principle of:
“robbing Peter to pay Paul.”

It is not enough that skin exists nearby — it has to be:

  • accessible

  • mobile

  • well matched

  • safe to recruit

Reserve helps determine:

  • whether a flap is feasible

  • which flap is most sensible

  • where tension should be redirected from

S – Solution

This may involve:

  • primary closure

  • advancement flap

  • rotation flap

  • transposition flap

  • interpolation flap

  • graft

  • secondary intention

  • staged management

  • referral

The best solution is not necessarily the most elegant or complex. It is the option that best balances:

  1. oncological safety

  2. function

  3. cosmesis

  4. technical appropriateness

  5. operator capability

This step should also include:

  • backup plans

  • margin-involvement contingencies

  • escalation decisions if complexity exceeds the setting or operator

PIG CARTS – Methods of Closure

(Robert Paver)

How to close the defect

P – Primary Closure

Direct closure where tissue laxity allows.

  • Ellipse / fusiform excision / diamond excision

  • M-plasty or S-plasty to optimise scar length and direction

  • ‘W-plasty’ and ‘geometric broken line’

I – Interpolation Flap

Two-stage flap using non-adjacent tissue with an intact pedicle.

  • Paramedian forehead flap (nasal reconstruction)

  • Nasolabial interpolation flap

  • Melolabial flap

G – Graft

Transfer of skin without its own blood supply.

  • Full-thickness skin graft (e.g. preauricular, postauricular donor - primary donor site closure)

  • Split-thickness graft (e.g. lateral thigh donor - secondary intention healing donor site)

  • Composite graft (skin and cartilage)

  • Halo-graft

  • Pinch graft

C – Complex (Combined)

Combination of techniques when a single method is insufficient.

  • Flap with residual graft

  • Partial closure with secondary intention

  • Multi-flap reconstruction for larger defects

A – Advancement Flap

Linear movement of adjacent tissue into the defect.

  • V to Y advancement flap

  • A to T flap

  • H plasty (bilateral advancement)

  • O to Z plasty (Harry Potter flap)

  • Island advancement flap (KPIF)

R – Rotation Flap

Curved movement of tissue to redistribute tension over a wider arc.

  • Simple rotation flap

  • O to S flap (double rotation)

  • Banner flap

  • Reiger flap (dorsonasal flap) - single stage axially based rotation/advancement flap

T – Transposition Flap

Tissue transferred across intervening skin.

  • Rhombic (Limberg) flap

  • Bilobed flap (commonly used on nose)

  • Z-plasty (tension redirection and functional release)

  • Banner flap

  • Popliteal W plasty

S – Secondary Intention

Healing by granulation and contraction.

  • Medial canthus

  • Conchal bowl of ear

  • Selected scalp or temple defects